Generally, ropes are widely used in, for example, the mooring of ships, or car coupling. In particular, since a strand wire rope as a high-strength fiber composite cable such as a carbon fiber composite cable has characteristics such as high strength, light weight, high corrosion resistance, and a non-magnetic property, it has been used as, for example, a reinforcing material for a concrete structure such as a pier or a prestressed concrete bridge in a corrosive environment; a tensile material for a high corrosion resistant ground anchor; a reinforcing core material for an overhead transmission line with less deflection; and a reinforcing material for a non-magnetic concrete structure (e.g., a guideway for a magnetic levitation train).
In order to use these ropes for the above-described purposes, a terminal of a rope must be processed using a terminal fixing tool such that the terminal is suitable for coupling.
However, some ropes may sometimes fall off the terminal fixing tool when a tensile load is applied to the ropes, because the fastening power by the terminal fixing tool is weakened due to the diameter reduction of the ropes. Further, as for the high-strength fiber composite cable, while it has high strength comparative to a PC steel strand wire when tensioned in an axial direction, it is vulnerable to a surface flaw, the local shearing force in a diametrical direction, and so on. Thus, in attaching the terminal fixing tool to the rope, a fixing method by directly inserting a wedge, which may be employed as a normal method for fixing a PC steel strand wire, easily causes cutting of the rope due to the shear failure, and as a result, high fixing efficiency cannot be achieved.
As measures to address the above problems, rope terminal fixing methods have been proposed in, for example, a publication of a patent application filed by the applicants (Patent Document 1) and a patent owned by the applicant (Patent Document 2). These fixing methods are suitable for use at a construction site.
In the fixing method of Patent Document 1, after a terminal of a rope is inserted into a tubular hole of a tubular metal fitting, at least one large-diameter chevron portion formed on the tubular metal fitting is reversely protruded on the tubular hole side by swaging, such that the rope is fixed while increasing the area of contact between the tubular metal fitting and the rope. In the fixing method of Patent Document 2, an expansion material filling socket is used to avoid the local concentration of stress in processing of a terminal of a high-strength fiber composite cable. Specifically, a partition member comprising a cable insertion hole and filler passage holes around the cable insertion hole is fit over the terminal of the cable, the cable is then inserted into a sleeve such that the partition member is located in the longitudinal center of the sleeve, and subsequently, water stop tools are attached to both ends of the sleeve. Then, the expansive filler such as cement is injected through the filler passage holes of the partition member to fill up the entire sleeve. After that, the expansive filler is cured, such that the cable terminal is fixed by friction due to expansion pressure of the expansive filler.